docstr: Get the scalar from model train summary
  Return list of summary data of [iteration_number, scalar_value, timestamp]
  
  :param tag: The string variable represents the scalar wanted
docstr_tok: ["Get","the","scalar","from","model","train","summary","Return","list","of","summary","data","of","[","iteration_number",",","scalar_value",",","timestamp","]",":","param","tag",":","The","string","variable","represents","the","scalar","wanted"]
code: def get_train_summary(self, tag=None):
      """
      Get the scalar from model train summary
      Return list of summary data of [iteration_number, scalar_value, timestamp]
  
      :param tag: The string variable represents the scalar wanted
      """
      raise NotImplementedError
  
file_path: analytics-zoo/pyzoo/zoo/orca/learn/spark_estimator.py
imports: from abc import abstractmethod
  from zoo.orca.learn.base_estimator import BaseEstimator
label_desc: Use image node_id 11 for calling the Estimator obj's underlying member method code with example usage: obj.get_train_summary(tag) without return types